Leather-stretching device.



PATENTED JAN. 3, 1905.

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A M Z mmm wwm W n mm W if m m N WW UNTTED STATES Patented January 3, 1905.

PATENT OEEIcE.

LEATHER-STRETCHING DEVICE.

SPECIFICATION "forming part of Letters Patent No. 778,900, dated January 3, 1905.

Application filed April 15, 1904. Serial No. 203,262.

To (LU whom it may concern:

Be itknown that I, GEORGE B. ROWBOTI-IAM, a citizen of the United States, and a resident of Boston, county of Suffolk, State of Massachusetts, haveinvented certain new and useful Improvements in Leather-Stretching Devices, of which the following is a specification.

This invention relates to devices for stretching leather; and it consists in certain improvements by which the apparatus is particularly adapted to hold and stretch pieces of hide or leather having an irregular outline without involving any loss or waste due to the failure to fully stretch all portions of the hide.

In the accompanying drawings I have illustrated one form of embodying my aforesaid invention; but it will be understood that changes may be made in the details of the construction and arrangement actually shown and described without departing from the spirit of my invention.

In said drawings, Figure 1 represents a plan view of a device embodying one form of my invention. Fig. 2 is a longitudinal cross-section thereof. Fig. 3 is a detail view of the under face of one of the independent clamping members. Fig. 4 is a side elevation of one of said clamping members.

As those skilled in the art know, it is the practice, particularly in the manufacture of belt-leather, to cut the hides or butts into longitudinal strips, each of these strips being put into a stretching-frame and subjected to pressure to stretch them. As one end of the butt has an irregular or asymmetrical edge, an ordinary form of clamp is not adapted to grip this edge to the best advantage. By the use of my improved device on this irregular edge, which varies in shape in different pieces of leather to be stretched, I am able to secure a powerful and permanent gripping action at the extreme end edge of the butt whatever its shape may be, thereby obtaining a full stretch or distension of every part of the hide or strip.

The device in general comprises a supporting-frame provided with a holding-clamp and a movable or stretching clamp, both of which are adapted to grip opposite ends of the hide or piece to be stretched and then subjected to a stretching strain or tension. It is immaterial for the purpose of my invention whether one or both of these clamps are made movable. It will suifice if one of them moves, while the other is bolted or otherwise secured in rigid engagement with the supporting frame or plank.

According to the form of my invention illustrated in the drawings I have provided a supporting frame. or plank (0, upon which is mounted a traveling clamp b of any suitable construction, one of whose members is provided with a pawl 6, arranged to engage the teeth of a rack-bar 0. At one end of the supporting-frame a is secured a holding-plate d, which in this case is provided with a series of ways in the form of longitudinal slots, as shown at (Z These longitudinal slots are provided with a series of independently-movable clamping members d constructed to pinch and grip the edge of the hide against the plate d. As herein shown, these individual clamping members are made in the form of plates d provided with small projecting teeth d said plate having a bolt-hole through its central portion, as shown at d. These teeth are preferably made blunt at their ends, so as not to injure the hide or leather, which they firmly grip. They are held in place and clamped against the holding-plate d by any suitable means. The means herein shown for that purpose consist of a bolt 0, having a squared head or flange e, fitting easily within the slot or way d and having its shank passing up through the bolt-hole (Z the upper end of the shank being screw-threaded to be engaged by a thumb or other nut 6 Suificient space is provided between the bottom face of the holding-plated and the underlying portion of the board a to give the head of the bolt the proper play lengthwise of the board.

As the butt-end of the hide or strip when in position will extend somewhat diagonally or obliquely across the plank or frame, the slots near one side of the plate may be made longer than the slots on the other side. The plate shown in the drawings is a plate such as would be adapted to stretch the right-hand side of the butt. These plates may be made rights and lefts, or for the purpose of stretching a whole hide could be secured to the same IOC plank. In order to give a better gripping action, the upper face of the holding-plate (i may be scored to form small corrugations.

It will be observed that the fixed corrugated and slotted plate CZ forms one member of the clamp with its corrugated face directly engaging the under side of the hide, while the small plates d collectively form the other member of the clamping device, whose forward series of teeth or projections 0Z pinch the extreme edge of the hide directly against the corrugations of the plate 61, while their rear set of teeth are adapted to form a direct engagement with the corrugations of the large plate. The fastening-bolts passing through their central apertures serve the double purpose of gripping the hide and holding the clamp members against movement.

Without attempting to set forth all the changes in form, construction, and arrangement that may be made in the embodiment of my invention or all the uses to which it may be applied, what I claim is 1. A device for stretching leather embracing in its construction, a supporting-frame, a movable clamp mounted thereon, a hide-holding plate secured to said frame and having its upper face corrugated, a series of separate adjustable hide-clamping plates having their bottom faces provided with projecting teeth, and fastening-bolts for drawing said individual clamping-plates directly against the corrugated holding-plate so as to pinch the edge of the hide agaist said holding-plate, substantially as described.

2. A leather-stretching device embracing in its construction a supporting-frame, a stationary hide-clamping device secured thereto and comprising a fixed member provided with slots extending lengthwise of the frame and having its upper face corrugated to grip the hide, and a series of opposing members adjustably arranged in the slots of the fixed member, and bolts for adjusting the clamping member against the fixed member to pinch and grip the extreme edge of the hide so as to hold it against the fixed member, and a rnovable stretching-clamp arranged to grip and stretch the opposite end of the hide, substantially as described.

3. A leather-stretching device embracing in its construction a supporting-frame provided with a movable stretching-clamp and having rigidly secured near one end a hide-clamping plate provided with longitudinal slots and having its outer face provided with transverse corrugations, a series of smaller hide-clamping plates provided with bolt-holes in their middle portions and having arranged on opposite sides of said hole a series of projections one set for pinching the hide against the fixed corrugated plate and the other set arranged to form a direct holding engagement with said corrugations, and clamping-bolts for securing said plates in their different positions of adjustment in order to pinch the hide against the corrugated plate and hold it against movement, substantially as described.

In witness whereof I have hereunto set my hand this 7 th day of April, 1904.

GEORGE B. ROWBOTHAM.

In presence of FRANK W. CARTER, GEO. N. GODDARD. 

